Endocrine Abstracts

Background: Acromegaly is associated with increased lean mass (LM) and reduced fat mass (FM), therefore body mass index is not a reliable parameter of body composition in this context. Moreover, the contributing factors to these alterations, along with their potential reversibility after achieving disease control, remain poorly understood. This study aimed to detect body composition alterations, as well as to investigate the impact of biochemical control and different medical treatments, in patients with acromegaly.

Methods: In this cross-sectional, case-control study, consecutive patients with active acromegaly (ACRO) were compared with age and sex-matched healthy controls (CTRL). Anthropometric and hormonal parameters were recorded. Total and region-specific body composition parameters were assessed via dual-energy x-ray absorptiometry (DEXA) scanning, measuring visceral adipose tissue (VAT), LM, and FM percentages. Appendicular lean tissue (ALT) and overall skeletal muscle index (SMI) were then calculated according to standardized formulae. Disease control of acromegaly was defined by IGF1 levels per upper limit of normal (IGF1×ULN) <1.2. Statistical analysis was performed with parametric and non-parametric tests, as appropriate. Data are expressed as mean±standard deviation or median (interquartile range) according to data distribution. Statistical significance was set at P<0.05.

Results: 40 patients with active acromegaly (ACRO) [22 males, median age 56.5 (41-64)] and 20 matched controls were enrolled. Among ACROs, 23 patients presented with biochemical control, 23 were on somatostatin analogs (SSAs), 9 were on pegvisomant (PEG), either as monotherapy or in combination with SSAs, and 8 patients were naïve to medical treatment. ACROs exhibited higher ALT (P=0.032) and a trend towards higher SMI (P=0.065) compared to CTRLs. In ACROs, no differences in body composition parameters were detected based on disease control status, except for a trend towards lower trunk fat (P=0.056) and higher total lean mass percentage (P=0.070) in poorly controlled patients. GH negatively correlated with VAT (r=-0.404, P=0.016), total (r=-0.486, P=0.003) and trunk (r=-0.564, P<0.001) fat percentage; IGF1xULN positively correlated with total lean mass percentage (r=0.312, P=0.050). Lastly, after stratifying ACROs according to type of medical treatment, no significant differences in body composition parameters were observed among SSA-treated, PEG-treated, and naïve patients.

Conclusions: Our analysis revealed increased lean tissue and skeletal muscle mass in patients with acromegaly compared to matched controls. These changes seem, in part, linked to the direct impact of hormonal excess; however, the role of different medical treatments requires further clarification.